Research on the Needle-Type Capacitance Method for Measuring Moisture Content in Grains

A needle-type capacitance method is proposed for measuring moisture content in grains. The higher sensitivity,stability and better response of the measurement are achieved by means of a needle-type capacitor sensor, a high-sensitive circuit capable of accurate measuring changes in capacitance and effective measures for reducing medium loss. The experimental results show that there is a good linear relationship between the moisture content in grain and the output voltage. This method gives a new way for the accurate, quick and in-situ measurement of moisture content in grains.